The invention relates to an injection system for injecting fluid into an exhaust tract.
Installing a particle filter in an exhaust system of an internal combustion engine of a vehicle is already known. If the internal combustion engine is a diesel engine, for example, the particle filter acts as a soot filter, for example, and through its filtering action reduces the fine dust pollution. In order to prevent the filter clogging after a certain period of service, it is necessary to regenerate the filter from time to time. The regeneration is performed by increasing the temperature to around 600 degrees Celsius, for example, resulting in combustion of the particles, in particular soot particles. Since engine measures will not allow this in all operating conditions, the increase in temperature is achieved by means of fuel, for example diesel fuel, which is injected into the exhaust tract via an injection valve. The injected fuel reaches an oxidation catalytic converter, which is arranged upstream of the particle filter. The fuel reaching the oxidation catalytic converter is oxidized or burned and leads to an increase in the temperature of the exhaust gas, so that correspondingly hot exhaust gases reach the downstream particle filter, where they bring about the regeneration.
Methods and devices for the regeneration of a particle filter are described, for example, in DE 10 2005 034 704 A1, DE 10 2006 062 491 A1 and DE 10 2006 057 425 A1.
The hitherto known systems for injecting fluid into an exhaust tract can be used only for a single exhaust tract and do not permit any increase in the quantity of fluid injected.